It's different from original Traveller. The system is pretty nice (though it has its faults, as every system does).

My only issue with the original 2300AD was the space combat system. It was...and there is no other word for it...boring. Sure, it's realistic, whereby space combat is more like modern submarine combat, but our group found it incredibly tedious.

In the end, we handwaved space combat and didn't include it much.

Other than space combat, however, it's a great system, although I've "hacked" it twice: once into Traveller: The New Era rules (essentially Twilight: 2000 v2.2), and I'm currently converting it into the Reflex system (from Twilight: 2013)

__________________
Every atom in our bodies was forged in the furnace of ancient stars. I like to think it's our destiny to return home...